Mastery Gem

Alter: This red gemstone seems to glint with some sort of liquid inside. The gem is impervious to attacks and damaging effects. The gem contains magic absorbed from countless other sources that it uses to overpower the requirements of certain item attunements. While holding this gem against an item with an attunement requirement you don't meet, you can ignore that requirement and attune to the item anyway. The item can't be legendary or an artifact. The gem fuses to the surface of the item and encases the area around it in a crystalline shell.

You can unattune to the new item as normal, even if the item is cursed. Unattuning to a cursed item in this way breaks the curse's effects on you. When you unattune to an item in this way, the gem detaches from the item, allowing you to use it on another one. The crystalline shell remains on the unattuned item. When you remove the crystal in this way, it takes the item's magic with it; turning the unattuned items into a mundane and nonmagical item.

Attunement: no
Rarity: Legendary
Type: Item
Cost: ???

Griffons Saddlebag, Vol 1